DIAGNOSTIC VALUE OF ACTIVITY OF MALIC DEHYDROGENASE AND PHOSPHOHEXOSE ISOMERASE: PRELIMINARY REPORT OF FINDINGS IN PATIENTS WITH MYOCARDIAL INFARCTION AND LIVER DISEASE

• The concentrations of three enzymes (malic dehydrogenase, phosphohexose isomerase, and aminopherase) were determined in the blood plasma of 18 patients with myocardial infarction, and the figures were compared with electrocardiographic findings, blood pressure, sedimentation rate, and leukocyte count. The same enzymes were determined in plasma from 14 patients with liver disease, and the figures were compared with the quantitative results of other chemical tests for liver function. The levels of the three enzymes studied were elevated in all of the cardiac patients, sometimes to a striking degree. The malic dehydrogenase level, for example, reached a maximum of 1,290 units, compared with a normal average of 79 units with a standard deviation of 20. The maximum levels occurred 24 hours after the onset of pain. In the patients with hepatic disease the concentrations of the three enzymes were also generally elevated; the highest values were obtained in patients with infectious hepatitis. The determination of the concentrations of malic dehydrogenase and phosphohexose isomerase is not difficult, and the results are informative.